1. Field of Use
This invention relates to time of day clock circuits and more particularly to apparatus for powering such circuits.
2. Prior Art
Battery operated portable microcomputer systems are well known. One such system is described in the article "Design Techniques for Microprocessor Memory Systems" by A. Thampy Thomas published in the August 1975 issue of the publication "Computer Design". Such systems include a non volatile memory system constructed from CMOS memories which have extremely low standby power dissipation in addition to a standby rechargeable battery with a diode to keep the battery from discharging into the turned off power line.
Additionally, similar battery arrangements have been used as backup power sources in minicomputer systems for providing auxiliary power in the event of power failures. When battery arrangements are included in timer devices, they have given such devices the same feature of portability. In such arrangements, the timer devices operate as free standing units rather than being integrated into a computer system.
Accordingly, it is a primary object of the present invention to provide an improved time of day device.
It is a further object of the present invention to provide a time of day device which can be easily integrated into a data processing system.